using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

public class ShinyThings : MonoBehaviour
{
    public WorldCursor Cursor;
    //Attributes for Highlighting of Facts when Mouse-Over
    private List<FactObject> LastFactSelection = new();

    //Variables for Pushout-Highlighting
    private static float timerDuration = 2.5f;
    private static float lerpTime = 1f;

    private IEnumerator rain_wait;
    private IEnumerator rain;

    public Light directionalLight;
    private Color darkColor = new(0.2f, 0.2f, 0.2f);
    private Color light_colour;
    private GameObject active_rainwork;

    public GameObject
        Fireworks_Animation,
        RainPrefab;


    private void Awake()
    {
        CommunicationEvents.PushoutFactEvent.AddListener(HighlightFact);
        CommunicationEvents.PushoutFactFailEvent.AddListener(LetItRain);
        CommunicationEvents.AnimateExistingFactEvent.AddListener(HighlightFact);
        CommunicationEvents.AnimateExistingAsSolutionEvent.AddListener(HighlightWithFireworks);

        rain = rain_wait = IEnumeratorExtensions.yield_break;

        if (Cursor == null)
            Cursor = GetComponent<WorldCursor>();

        if (directionalLight == null)
            directionalLight = FindObjectOfType<Light>();

        light_colour = directionalLight.color;
    }

    public void Update()
    {
        if (Cursor?.Hits != null)
            HighlightCurserHit(Cursor.Hits);
    }

    private void HighlightCurserHit(RaycastHit[] hits)
    {
        List<FactObject> selected_fact_objs = hits
            .Select(h => h.transform?.GetComponentInChildren<FactObject>())
            .Where(f => f != null)
            .ToList();

        //Set the last Facts unselected
        foreach (var lastFact in LastFactSelection)
            if (lastFact != null
             && !selected_fact_objs.Contains(lastFact))
                ApplyMaterial(lastFact, lastFact.Default);

        //Set the Facts that were Hit as selected
        foreach (var fact_obj in selected_fact_objs)
            if (!LastFactSelection.Contains(fact_obj))
                ApplyMaterial(fact_obj, fact_obj.Selected);

        LastFactSelection = selected_fact_objs;
        return;

        void ApplyMaterial(FactObject root, Material new_mat) =>
            root.CoroutineCascadeForMeAndChildrenAllRenderer(
                (_, renderer) =>
                    renderer.ProgrammMaterialChange(new[] {
                            (0f, lerpTime, new_mat),
                    })
                );
    }

    public static void HighlightFact(Fact startFact, FactObject.FactMaterials tmp_mat)
    {
        if (startFact.Representation == null)
            return;

        FactObject selected_fact_obj = startFact.Representation.GetComponentInChildren<FactObject>();

        selected_fact_obj.CoroutineCascadeForMeAndChildrenAllRenderer(
            (fact_obj, renderer) =>
                renderer.ProgrammMaterialChange(new[] {
                    (0f, lerpTime, fact_obj.materials[(int) tmp_mat]),
                    (GlobalBehaviour.hintAnimationDuration, lerpTime, fact_obj.Default),
                })
            );
    }

    public void HighlightWithFireworks(Fact fact, FactObject.FactMaterials mat)
    {
        rain_wait = IEnumeratorExtensions.yield_break; //stop rain

        StartCoroutine(BlossomAndDie());
        HighlightFact(fact, mat);

        IEnumerator BlossomAndDie()
        {
            GameObject firework = GameObject.Instantiate
                (Fireworks_Animation
                , fact.Representation.transform
                );

            yield return new WaitForSeconds(timerDuration);

            firework.transform.GetChild(0)
                .GetComponent<ParticleSystem>()
                .Stop();
            var sparks = firework.transform.GetChild(1)
                .GetComponent<ParticleSystem>();
            sparks.Stop();

            while (sparks.IsAlive())
                yield return null;

            GameObject.Destroy(firework);
        }
    }

    public void LetItRain(Fact startFact, Scroll.ScrollApplicationInfo _)
    {
        // check if couroutine is waiting or finished 
        if (!rain_wait.MoveNext() || !rain.MoveNext())
        {
            StopCoroutine(rain);
            StartCoroutine(rain = BlossomAndDie());
        }
        rain_wait = 0f.LerpInTime(0, timerDuration); //reset timer

        IEnumerator BlossomAndDie()
        {
            Destroy(active_rainwork);
            active_rainwork = GameObject.Instantiate(RainPrefab, new Vector3(0, 40, 0), Quaternion.identity);

            Color start = directionalLight.color; // may not be original one
            for (IEnumerator<float> lerper = MathfExtensions.LerpInTime(0, 1, lerpTime)
                ; lerper.MoveNext();)
            {
                directionalLight.color = Color.Lerp(start, darkColor, lerper.Current);
                yield return null;
            }

            while (rain_wait.MoveNext())
                yield return null;

            for (IEnumerator<float> lerper = MathfExtensions.LerpInTime(0, 1, lerpTime)
                ; lerper.MoveNext();)
            {
                directionalLight.color = Color.Lerp(darkColor, light_colour, lerper.Current);
                yield return null;
            }

            GameObject.Destroy(active_rainwork);
        }
    }
}